Loudspeaker



FIG. 1 is a perspective view of a loudspeaker incorporating the ornamental design;

FIG. 2 is a front view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a side view thereof; and,

FIG. 5 is a rear view thereof. 

The ornamental design for a loudspeaker, substantially as shown and described. 